.border_b{
   border: 1px solid #000000;
}

.float{
   visibility: hidden;
   position: absolute;
   left: -3000px;
   z-index: 10;
}

#enmedio {
   background:white; 
   padding:5px;
   border:0px solid darkgray;
   text-align:center;
}

.imagenenmedio {
   border: 1px solid gray;
   padding: 5px;
}